The research proposal objective is to develop dynamic nuclear polarization (DNP) techniques for MR studies of heart. DNP enhances nuclear spin polarization and thus MR signal 10,000-fold, enabling one to track the metabolism of cellular substrates in vivo using 13C MR spectroscopy. Initial work will involve setting up the hyperpolarizer methods and protocols that will allow rapid administration of hyperpolarized tracer to rat hearts. Monitoring of in vivo metabolic reactions will be verified using in vitro 13C MR spectroscopy. Baseline metabolite labeling and vascular imaging will be established in normal heart in vivo, and then models of heart disease will be studied to determine differences in substrate uptake and metabolism. This information will link cellular metabolism with whole heart function. It is anticipated that differences in heart metabolism may be examined to determine the metabolic status of human heart for early diagnosis of disease. [unreadable] [unreadable] [unreadable]